definitely wash your hands often - players are gross people, and the chips and cards carry their grossness. I know a lot of players who will wear gloves, I should do it too but dont.
Never play live outside what your
bankroll suggests. The most common tell live players pick up is fear, and the most common fear is playing outside your limits. Scared money is the most easily won.
If you are really nervous try beta-blockers, natural or in pill form. They will lower your heart rate and make you seem calmer than you really are, which is the important part of it. Who cares if your nervous, just dont let others know it.
Two hours is not a bad session for first time. Get your feet wet, figure out the pace.
With this take something to keep your mind occupied, being an online player you will often get bored live because it is way way slower and you can only play one hand, one game, at a time. Bring an
App device or a book to read if you get bored easily...because bored players play way too loose...and most live games are action packed where loosemess only helps the gambler types who have a bunch of buy ins in their pocket and dont care about money anyways - tight is right especially to a live novice.
Good luck in the future - where are you playing? What state what casino?